<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .radar {
            overflow: hidden;
            position: relative;
            margin: 200px;
            width: 200px;
            height: 200px;
            border-radius: 50%;
            background: #fff;
            border: 1px solid #5ef2ff;
            box-sizing: border-box;
        }

        .radar::before {
            width: 100px;
            height: 200px;
            content: '';
            display: block;
            position: absolute;
            right: 0;
            top: 0;
            box-sizing: border-box;
            border-left: 1px solid #5ef2ff;
        }

        .radar::after {
            width: 200px;
            height: 100px;
            content: '';
            display: block;
            box-sizing: border-box;
            border-bottom: 1px solid #5ef2ff;
        }

        .fan {
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            border-radius: 50%;
            box-sizing: border-box;
            border: 1px solid #5ef2ff;
            width: 100px;
            height: 100px;
        }

        .fan::after {
            content: "";
            width: 100px;
            height: 100px;
            display: block;
            box-sizing: border-box;
            position: relative;
            top: -50%;
            right: -50%;
            transform-origin: 0% 100%;
            border-bottom: 3px solid transparent;
            border-image: linear-gradient(to right, transparent, #5ef2ff);
            border-image-slice: 3;
            background: transparent;
            background-image: linear-gradient(to right, transparent, #9bfdfd);
            animation: rotateAnimate 2s linear infinite;
        }

        @keyframes rotateAnimate {
            from {
                transform: rotate(0deg) skew(-10deg)
            }

            to {
                transform: rotate(360deg) skew(-10deg)
            }
        }
        .box{
            width: 100px;
            height: 100px;
            border:1px solid #cccccc
        }
    </style>
</head>

<body>
    <div class="box"></div>
    <div class="radar">
        <div class="fan"></div>
    </div>
</body>

</html>